1. Field of Invention
This invention relates generally to an improved method for fabricating a manual drip coffee cone. An improved design is needed for manual drip coffee cones that can be easily fabricated from material in flat sheet form, such as sheet metal.
2. Prior Art
A manual drip coffee cone is a common type of coffee maker used worldwide. These cones are designed to sit on top of a coffee cup or carafe. Water is poured through a cone holding a filter with coffee grounds, so that coffee drips into the cup or carafe below. This simple coffee-making tool is compact, quick and easy to use and clean, and inexpensive to buy. Following is a discussion of problems with prior art.
Problems with Designs for Molded Materials
Most modern designs for coffee cones are tailored to fabrication with glass, ceramic, or plastic material in a molding process. A cone design for a molded process is not compatible with sheet metals such as stainless steel, aluminum, and others. Molded designs have multiple protruding elements on the conical body and ring collar that are easily turned out in a mold, but that are cost prohibitive to achieve with sheet materials. Sheet metal is commonly drawn or spun. However, most modern coffee cone designs are limited to molten molded fabrication. Molten fabrication with metal is cost-prohibitive. The problem to solve is to create a superior and cost-effective cone design for fabrication with sheet materials so that sheet metal, such as stainless steel, and other sheet materials can be used.
There is a currently un-answered need for metal coffee cones. A modern-style metal coffee cone would offer a new choice to consumers who are looking for lightweight alternatives to plastic. Metal has the light weight and durability of plastic, and the inert surface chemistry of glass and ceramic that resists odors, scratching, and flammability. Unlike plastic, metal cones will not melt when placed near an open flame, or hot stove burner. Metal has better taste than plastic kitchen utensils because metal does not retain food odors. Even after cleaning them, coffee drippers made of plastic often retain a rancid coffee taste. Another problem is that as a petroleum product, plastic coffee cones can be perceived to pose a health risk. Plastic ingredients, such as phthalates and bisphenols, can be perceived to have the potential to leach into hot liquids prepared in plastic kitchenware. Manufacturing byproducts of plastic, such as propylene from molded polypropylene thermoplastic resin, can also be perceived to be toxic. Concerns such as these are enough to stimulate a consumer demand for a coffee cone that is made of metal material, such as stainless steel. Metal is superior to plastic for reasons of health, environmental concerns, aesthetic choice, durability, and taste. Many consumers are switching from plastic kitchenware and plastic water bottles to stainless steel. Glass and ceramic are not superior alternative materials for coffee cones because they easily break when dropped. Therefore, a coffee cone design is needed that can be most economically made from metal, and particularly, made easily from the form of flat sheet metal.
Ineffective View Beneath the Cone
A superior design should have a ring collar that provides an easy view beneath the cone in order to see the rising level of the coffee in the cup below. It is a great advantage to see through to the coffee below so that the user does not have to lift the cone off the cup during the dripping process in order to see when coffee dripping is done. Without a view, the user often pours too much water into the cone. The receiving cup spills over because the user cannot see when to stop. Some plastic cones disclosed by prior art provide a limited view beneath the cone, but none allow a full view. To simplify fabrication for sheet materials, and also to provide a full view through the ring collar, the ring collar needs to have the simplest shape and least possible surface area.
Solving Problems of Prior Art
Two aspects of prior art need to change to make an efficient coffee cone design for sheet material, such as sheet metal:
1) Problematic Drip Ring Width: The drip ring must be the base of the conical body, rather than attached as a separate component to the base of the conical body or ring collar. This simplifies construction by reducing the number of components attached to the cone. In molded designs, additional components are part of a mold that turns out protruding features in one step. In contrast, using sheet materials, all protruding elements must be fastened to a main body as separate components that each have additional fabrication steps. Therefore, it is necessary to simplify the number of protrusions when designing for sheet materials in order to eliminate additional attachment steps. In a design for sheet materials, it is most efficient for the base of the conical body to be one in the same as the drip ring.
In contrast, prior art discloses drip rings that are most compatible with molded fabrication. Drip rings disclosed by prior art are not the same width as the base of the cone, and so would have to be attached in an additional step if using sheet material. Examples of prior art that disclose a drip ring with a different width than the base of the conical body are foreign patent JP10286180 to Tanaka (1998) FIG. 6A, and foreign patent LU48391 to Bentz (1965) FIGS. 6B and 6C. Tanaka discloses a drip ring that is wider than the base of the cone FIG. 6A. Bentz discloses one drip ring that is narrower than the base of the cone FIG. 6B, and one that is wider FIG. 6C.
2) Superior See-Through Ring Collar: The shape of the ring collar must be simple in order to facilitate construction. Simultaneously, the ring collar should provide the best possible view through it to see beneath the cone. To achieve this, the mass and surface area of the ring collar should be reduced to the fullest extent. This also saves overall weight and material costs.
The ring collar should be fabricated in the configuration of a flat plane, as a frame. It is presently envisioned that one preferred design has a ring collar with three radial spines connected to the outside of the cone that support the cone to sit on its cup. This is similar to a wheel with three spokes. A ring collar with the simplest shape, minimal number of components, and least possible surface area will allow the fullest view to the cup below, and have the least overall weight, and least material costs. Such a frame can be made from metal tubular wire, or similar construction. With the ring collar constructed as a wheel-and-spoke-style frame, the user does not have to adjust or move the cone to different angles to see into the cup below because no angle of vision is obstructed. Such a minimal frame cannot be achieved with plastic material. A wheel-and-spoke style frame made of plastic would not have enough structural integrity to withstand equal force and so would easily snap and break. Thin rods or spokes are far stronger in metal material than plastic. Prior art has not disclosed a spoke-style ring collar that is flat. The same frame in plastic would require much greater surface area to withstand the same force. It is that greater surface area and mass of molded ring collars disclosed to date that obstructs the user's view to beneath the cone.
The simplest ring collar that a user can see through has two important elements. First, to facilitate fabrication, the ring collar should be constructed in a flat plane, and have a minimal number of support arms. Second, the ring collar should have the least possible surface area, in order to allow the best view through it. Wire tubing, or similar construction, such as with rods, is well suited to make such a frame.
Prior art that discloses inefficient views through the ring collar includes U.S. Pat. No. D203,854 to Douglas (1966) FIGS. 7A and 7B, U.S. Pat. No. 3,334,574 to Douglas (1967) (similar to FIG. 7A), and U.S. Pat. No. 2,835,191 to Clurman (1958) FIGS. 7C and 7D. The ring collars disclosed by prior art have overly complicated design features. Neither Douglas nor Clurman reduced the ring collar's surface area to the fullest extent possible. Further, Douglas discloses a ring collar that has a flared ramp shape, instead of a flat plane, which makes its fabrication more complicated and expensive if it were to be applied to use with sheet material. Similarly, the ring collar disclosed by Clurman is more complicated to fabricate than a flat planar shape because it has support legs that extend into the vertical plane. Additionally, the view through these ring collars is partially obstructed because a large surface of the ring collar remains and blocks the view to the coffee below at certain angles. This forces the user to adjust one's head or the cone itself in order to try to see clearly beneath the cone to inside the cup below.
One example of prior art made by the Japanese company ‘SnowPeak’ (Information Disclosure Statement By Applicant, USPTO form SB08b; Citation #2) discloses a collapsible folding ring collar on a metal cone. However, this ring collar is not a flat planar shape. Instead, it has a complicated interlocking set of four legs that extend out from the conical body in both the horizontal and vertical directions. Further, each leg has hinges that allow them to fold flat. All facets of the hinged legs that allow it fold make the overall supporting ring collar overly complicated and expensive to fabricate because multiple steps are required to attach each component. Also, the cone disclosed by Snow Peak has legs that do not have lateral support, making the cone unstable and easily tipped over.
These two changes to prior art simplify and improve it to create a most efficient and effective coffee cone design for fabrication with sheet materials such as sheet metals. These two changes simplify fabrication for the drip ring and a see-through ring collar. A superior cone design for sheet material must minimize the number of components because adding each one is costly. Simplifying the number of components also maximizes the cone's overall strength.
Two additional elements are necessary for a superior cone design—the height of the drip plate, and omission of interior ribbing.
1) Drip Plate Height: The level of the drip plate should not be set below the ring collar. Instead, the drip plate should be set at or near the same level as the ring collar in order to provide the maximum height of head space for dripping into the cup below. When a drip plate height is set too low inside its receiving vessel, then coffee filtration becomes submerged in the rising level of the coffee. This makes the water level back up inside the cone above, and hinders the filtration process. It is much more effective for drip filtration to occur above the rim of the cup. This is achieved by setting the drip plate at the same height as the ring collar. Examples of prior art that disclose a drip plate set too deep into its receiving vessel include U.S. Pat. No. 224,397 to Bentz (1941) FIGS. 8A and 8B, U.S. Pat. No. 4,221,670 to Ziemek and Kabel (1980) FIG. 8C, and U.S. Pat. No. 975,874 to Korn and Kuhn (1910) FIG. 8D.
2) Omission of Ribbing: There should not be vertical ribs inside the conical body. Ribbing complicates fabrication and adds expense, and is unnecessary for effective coffee percolation. Examples of prior art that disclose vertical ribbing inside the cone include Tanaka FIG. 6A, and Bentz (1941) FIGS. 8A and 8B. Much of the prior art describes ribbing on the interior wall of the cone as facilitating flow of coffee downward. However, coffee filters equally well when the cone has a smooth surface inside the cone. Funnels used in chemistry labs function similarly. In a chemical laboratory application, a conical funnel with a smooth interior is used with paper filters for extracting liquid solutions through particulate matter such as a saturated paste or soil. Just like these funnels, coffee cones also filter very well without vertical ribbing. One example of prior art made by the Bodum company (Information Disclosure Statement By Applicant, USPTO form SB08b; Citation #5) discloses a glass coffee funnel with a smooth interior. To include vertical ribbing in a metal cone not made from a mold, the ribs would have to be added onto the inside of the cone in an additional fabrication step. For instance, individual spines might be welded onto the inside of the cone, or grooves could be cut into the surface of an extra-deep sheet of metal. Ziemek and Kabel FIG. 8C attempt vertical ribbing by disclosing a corrugated conical body. However, this corrugation complicates and adds expense to the fabrication process. A corrugated surface also complicates attachment of the ring collar and drip plate to the conical body. Ribbing or corrugation must be omitted from an optimum cone design because it is unnecessary for filtration, and complicates fabrication. Instead, a smooth cone interior saves material and manufacturing expenses, and also is easier for the user to wash after each use.
Other design elements are changed in additional embodiments of the invention. Changed elements of additional embodiments include: A conical body with an oval-shaped base and drip ring; a drip plate hole with a sieve screen; an insulated conical body; and a solid ring collar.
Oval-Shaped Base and Drip Ring: An ovular shape for the base of the cone is more similar to standard paper filters that have a straight-shaped bottom (popularized by Melitta), and so may have wider consumer appeal than the circular shape of the base of the cone in the first embodiment. However, both the circular and the ovular shape for the base of the cone function equally well with the same paper filters. The drip ring that is the base of the cone is correspondingly oval-shaped, as is the drip plate and the ring collar where they attach to the ovular conical body.
Drip hole with sieve screen: It is also envisioned that the same design for a coffee cone can be made with a drip ring that has a large drip hole with a screen or sieve that acts as a filter. This embodiment does not require the use of a separate removable filter. It can be used with one optionally if the user desires to filter oils from the coffee, or to use a removable filter for easy disposal of the grounds.
Improved Insulation: A cone can be made more insulating by fabricating the conical body with double wall construction. A superior cone design would provide insulation for the coffee and for the user's protection. An additional embodiment of the invention is constructed with metal material as a double walled cone that has air or vacuum insulation. Insulation keeps hot water warmer as it drips through the cone and reduces cooling of the coffee. Insulation also affords the user protection from an overly hot cone surface while the person handles the cone during use. Vacuum-insulated double-walled construction has become popular in the manufacture of similar items, such as travel mugs and thermoses. A double-walled embodiment of the invention offers better insulating capacity than single-walled embodiments. However, a double-walled version costs more to produce. Therefore, it is important to create both single and double-walled versions, so that consumers have a price choice. Single-walled metal coffee cones operate as well as single-walled coffee cups that are commonly sold. That is, they work well enough, but if you can afford it, it is nicer to have double-walled. However, single-walled metal cups remain popular consumer items because they cost less. Therefore, it is expected that there is a demand for both single and double-walled versions of the cone.
Foreign patent DE2607605 to Schnause (1977) discloses an insulated conical body. However, insulation disclosed by Schnause is too narrowly limited to allow more modern innovations that use air or vacuum insulation between double walls. Schnause discloses a cone with insulation restricted to foam. In his Claims, Schnause limits insulation to foam as follows:
“4) Filter housing after 1) to 3), thereby characterized, that that warm damming material from a foam material molded article exists.
5) Filter housing after 1) to 4), by the fact characterized that Foam material molded article from PURE, PP, PE, PVC, PMM exists.
6) Filter housing after 1) to 5), by the fact characterized that the foam material molded article consists of a flexible material.
7) Filter housing after 1), by the fact characterized that it consists of an integral foam material.
8) Filter housing after 1) to 7), by the fact characterized that it consists of polyurethane integral foam.”
Schnause's claims are tailored to plastic molded cones. Schnause's claims do not provide for insulation compatible with metal construction as is provided by vacuum, or simply by air space. Another problem with the Schnause design is that the drip ring is not the same as the base of the conical body, and is a separate protrusion attached to the bottom of the ring collar. This limits its fabrication to molded methods, or else requires that the drip ring be attached to the conical body as a separate component in an extra fabrication step.
Solid Ring Collar: It is also envisioned that the same design for a coffee cone can be made as a less expensive version that does not provide a view beneath the cone. This embodiment has a simplified ring collar that is a solid plane. This embodiment has lower production costs. This provides consumers a choice of cone that offers all the benefits of metal's strength and inert surface chemistry, but that does not have the added expense of the frame-style ring collar.